I had a friend with the same issue several years back. For years he had a tiny small black spot on the side of middle toe. Went for dermatologist visit, who immediately removed what he could, sent him to a plastic surgeon the next day for complete removal.

A couple of days later the dermatologist called to tell him it was full blown melanoma. If it had "broken loose" there would be nothing he could do to help him.

And yes, I went for a full checkup and continue annually.

Dermatologist also told me Bob Marley died from melanoma on his foot.

Go get checked. And slather on the sunscreen.